The proposed experiments with the Mongolian gerbil (Meriones unguiculatus) derive from two general features of pheromone communication and social behavior: 1) basic aspects of pheromone production, transmission and reception depend on thermoenergetic features of the organism, and 2) much pheromone communication is metacommunication, acting to facilitate information exchange and reduce unnecessary energy expenditure. The first notion suggests that thermoregulatory processes and variations in diet will regulate critical aspects of pheromone communication. The second notion suggests that the understanding of olfactory communication will emerge when it becomes known how and under what conditions animals will seek and transmit information as opposed to decifering the message itself. Experiments under point (1) are described which vary metabolic state, and hence pheromone utilization. Experiments under point (2) are described which test for behaviors that lead to better access to conspecific signals and which integration of pheromone and other sensory systems (i.e., ultrasonic). In combination the theoretical and experimental approaches will lead to a better understanding of the physiological and behavioral conditions which facilitate information exchange among members of a species. Additional experiments proposed are for the purposes of (1) establishing a behavioral ethogram for M. unguiculatus and describing its burrow system, and (2) continuing our work on the Harderian pheromone system and related communication systems.